from __future__ import absolute_import, print_function, division

import warnings

import six

from .. import encoding, utils

if six.PY2:
    _native = lambda x: x
    _always_bytes = lambda x: x
else:
    # While headers _should_ be ASCII, it's not uncommon for certain headers to be utf-8 encoded.
    _native = lambda x: x.decode("utf-8", "surrogateescape")
    _always_bytes = lambda x: utils.always_bytes(x, "utf-8", "surrogateescape")


class Message(object):
    def __init__(self, data):
        self.data = data

    def __eq__(self, other):
        if isinstance(other, Message):
            return self.data == other.data
        return False

    def __ne__(self, other):
        return not self.__eq__(other)

    @property
    def http_version(self):
        """
        Version string, e.g. "HTTP/1.1"
        """
        return _native(self.data.http_version)

    @http_version.setter
    def http_version(self, http_version):
        self.data.http_version = _always_bytes(http_version)

    @property
    def headers(self):
        """
        Message headers object

        Returns:
            netlib.http.Headers
        """
        return self.data.headers

    @headers.setter
    def headers(self, h):
        self.data.headers = h

    @property
    def timestamp_start(self):
        """
        First byte timestamp
        """
        return self.data.timestamp_start

    @timestamp_start.setter
    def timestamp_start(self, timestamp_start):
        self.data.timestamp_start = timestamp_start

    @property
    def timestamp_end(self):
        """
        Last byte timestamp
        """
        return self.data.timestamp_end

    @timestamp_end.setter
    def timestamp_end(self, timestamp_end):
        self.data.timestamp_end = timestamp_end

    @property
    def content(self):
        """
        The raw (encoded) HTTP message body

        See also: :py:attr:`text`
        """
        return self.data.content

    @content.setter
    def content(self, content):
        self.data.content = content
        if isinstance(content, bytes):
            self.headers["content-length"] = str(len(content))

    @property
    def text(self):
        """
        The decoded HTTP message body.
        Decoded contents are not cached, so this method is relatively expensive to call.

        See also: :py:attr:`content`, :py:class:`decoded`
        """
        # This attribute should be called text, because that's what requests does.
        raise NotImplementedError()

    @text.setter
    def text(self, text):
        raise NotImplementedError()

    @property
    def body(self):
        warnings.warn(".body is deprecated, use .content instead.", DeprecationWarning)
        return self.content

    @body.setter
    def body(self, body):
        warnings.warn(".body is deprecated, use .content instead.", DeprecationWarning)
        self.content = body


class decoded(object):
    """
    A context manager that decodes a request or response, and then
    re-encodes it with the same encoding after execution of the block.

    Example:

    .. code-block:: python

        with decoded(request):
            request.content = request.content.replace("foo", "bar")
    """

    def __init__(self, message):
        self.message = message
        ce = message.headers.get("content-encoding")
        if ce in encoding.ENCODINGS:
            self.ce = ce
        else:
            self.ce = None

    def __enter__(self):
        if self.ce:
            if not self.message.decode():
                self.ce = None

    def __exit__(self, type, value, tb):
        if self.ce:
            self.message.encode(self.ce)